JPS6284745A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an ultrasonic diagnostic apparatus, and particularly to an ultrasonic diagnostic apparatus suitable for high-resolution, high-speed imaging.

[Background of the invention]

A conventional device (see Japanese Patent Application Laid-open No. 112234/1983) will be explained with reference to FIGS. 1 and 2.

As shown in the figure, it is equipped with two sets of phasing means (1, L),
For ultrasound beams in the same direction, the depth of focus is alternately switched, and when one phasing means is used, the receiving focus is moved by changing the tap of the other phasing means ( dynamic focus). In this case, it is necessary to prepare two sets of completely identical circuit configurations that cause switching noise. In addition to the tap switching described above, switching noise occurs when, for example, the array element aperture is changed with depth (variable element aperture), so it is necessary to prepare two sets of variable element aperture switchers.

The variable element diameter is described in Japanese Patent Laid-Open No. 140658/1983. That is, the element width W of the array element
By making W variable in the depth direction and controlling it so that W is small for short distances and large W for long distances, the number of circuits (ki-phase circuits) that give delay time to ultrasonic signals or signal lines can be reduced. The objective is to simultaneously improve short-range resolution and long-range resolution without increasing the number of sensors.

Third. The operation of the variable element aperture will be explained using FIG.

One example is a device in which a vibrator is divided into unit elements having a width Wo, a common delay time is given to m adjacent unit elements (m≧1), and m is made variable. According to this configuration, effective element width W=mW
o (m is a natural number), the desired control can be achieved by decreasing m for short distances and increasing m for long distances. As an example, FIG. 3 shows a configuration in which control is performed by changing the above-mentioned m as m=■, ■, ■ from a short distance to a long distance. In Fig. 3, the number of drive diameter divisions N=6, El to E18 are unit elements, and 81 to S6.
is a signal line, and C1 is a switching circuit that changes m by a switching signal Sφ. The transmitting driver circuit and receiving amplifier circuit are omitted from the diagram. The connection logic of the switching circuit C1 is shown in the table of FIG. Note that in the table of FIG. 4, N and C indicate no connection. That is, when the focal length is small, W=
~In order to set the mode to VO, select the contact point of C1 and press E7.
The unit elements of ~E12 are connected to 81~S6, respectively. In addition, in order to set the mode to W''2Wo at a medium focal length, select the contact point of C1, set E4 and E5 to Sl, set E6 and El to S2, and so on, unit element 2 Connect each one to one 1δ line.Furthermore, in order to set w=aWO mode when the focal length is large, select the contact point of C1, and set El-E2 and E3 to Sl,... and connect three unit elements to one signal line.By the above method, the effective element width W
can be controlled by changing it according to the focal length, without increasing the number of delay circuits or signal lines.
High resolution can be achieved at both short and long distances.

Conventional technology (Japanese Unexamined Patent Publication No. 56-11
2234), the switching 'a' in Figure 1
It is necessary to arrange two sets of switch C1 shown in FIG. 3 at the +1 input terminal for each phaser, which poses a problem of increased circuit scale.

[Purpose of the invention]

The object of the present invention is to provide high resolution ultrasonic diagnostic equipment.

The object of the present invention is to provide a simple configuration that realizes a receiving aperture, a receiving focal depth, etc. for high-speed imaging.

[Summary of the invention]

In order to move the depth of focus during the reception period (dynamic focus) for one wave transmission, a normal inductance-capacitance delay line (hereinafter referred to as LC delay line) is used as a reception phasing section. When changing taps,
This was not practical because switching noise was mixed into the signal. The present invention transmits waves twice, and sets the first tap switching time and the second tap switching time to be different, and combines the received signals for each transmitted wave. , which performs moving focus (dynamic focus).

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be explained using FIGS. 5 and 6. In FIG. 4 is a probe consisting of an array transducer, 5 is a preamplifier, and 6 is a delay element, such as a tapped inductance-capacitance delay line (L-C delay line), or a first switching A device that receives received signals from multiple channels within the receiving aperture and outputs the taps to select A so as to generate the necessary delay time to focus the received beam. It is. This first switching device may be a low-grade product that generates switching noise. 8 is an image processing circuit for compression, detection, etc.; 9
f'i analog-to-digital converter (A/D converter), 1
Line memories 0-a and 10-b store received signals for one scanning line (eg, 300 μS). 10-a is the first wave transmission trigger Trl, 10-is is the next wave transmission trigger Tv
Corresponds to t. 11 is a second switch, and the line memory 10-a.

10-b is read out alternately, and is a high-grade switch that does not generate switching noise. 12 is a display, and 13 is a phasing section.

In Fig. 6, the first time among the consecutive transmission triggers is T?
Den, next time will be T. In response to the first wave transmission trigger Trl, the reception focal point is moved from F+, F3, Fs, and Fy and stored in the line memory 1o-a. here,
The focus point is moved by the first switch 7. Next, for the next transmitting trigger Trt, set the receiving focal point to F2°Fa + Fs
e... and stored in the line memory 10-b. The switching times for the first and next wave transmissions are different times, and are set alternately, for example, as shown in FIG. If the second switching device 11 is controlled as shown in FIG. 6 after the reception interval (for example, 300 μs x 2 = 600 μs) of consecutive wave transmission triggers TrltTr2 has elapsed, the output of the second switching device 11 will be as shown in the bottom row. , the reception focal point is FI
'*)'! +F3.・・・・・・It is moved like F7. Therefore, a received signal that is not affected by the switching noise generated by the first switching device 7 is obtained and displayed on the display. (As mentioned above, the second switching device 11 is of high quality and does not generate switching noise.) When performing variable element diameter, the switching device C1 in FIG. placed between.

As described above, according to this embodiment, the real-time receiving wave focusing point is moved, but in order to obtain the receiving signal of one scanning line by transmitting the waves TN and Tr2 twice, the ultrasonic image is taken once. The image speed is reduced to 1/2 compared to the case without a moving focus.

A second practical example of the present invention, which does not solve all of these problems, will be explained with reference to FIGS. 7 and 8. The same numbers as in FIG. 5 indicate the same means. In this example, for the same transmission beam,
It forms multiple receiving beams that are slightly deviated. 13-1.13-1 is a phasing unit corresponding to each beam. As shown in FIG. 8, the two phasing units 13-1.13-II are simultaneously switched in response to the first wave transmission trigger TrI, and the focal positions are set to Fit p, /; F3. Fs
'; FSs Fs': FilF7'...
・Suppose. For the next wave transmission trigger Tr2, the two phasing units 13-1 and 13-II are simultaneously switched and the focal positions are set to F4, Fl', F4. F4': F
eeFs'; Fsg FB'...

Here, the focal position F I * F2 * of the phasing section 13-I
F3 t . . . and the focal position p, t,' Bv, /, F3/, . Something is off.

If the two second switching devices 11 are switched synchronously, a plurality of received beams 1 and 2 are obtained as outputs from each switching device 11, and are displayed on the display 12.

When performing variable element aperture, the switching device C1 in FIG. 3 is placed next to the preamplifier 5 in FIG. 7, and the switching device C1 in FIG. fdt, there are no 8 jars to do. - Therefore, variable element aperture and dynamic focus can be achieved with a simple configuration.

〔Effect of the invention〕

According to the present invention, it is possible to move the focal point without being affected by tap switching noise of the receiving wave phasing section, so there is an effect that a low-cost and simple phasing section can be realized.

[Brief explanation of drawings]

Figures 1 to 4 are explanatory diagrams of the prior art, and Figures 5 and 6 are
The figure shows one embodiment of the invention, and FIGS. 7 and 8 show other embodiments of the invention. - In Figure 3, b... tapped inductance.
Capacitance delay line, 7...first switch, 11...
- Second switch, 10-a, 10-b... line memory, 13... fire phase section. In Figure 5, -1-3
-1゜ho/I! 1 =y F+ Fz F F4 F3rd

Claims (1)

[Claims] 1. In an ultrasonic diagnostic device that focuses an ultrasound beam by controlling the phase of transmitted and received signals of a plurality of piezoelectric elements, the focal section is moved during the reception period with respect to the first transmission. The receiving phasing means is equipped with a reception phasing means which can be switched so as to switch the receiving phasing means so as to switch the receiving phasing means so as to switch the phasing means to the ultrasonic beam in the same direction as the above for the next wave transmission, at a time different from the switching time during the reception period. An ultrasonic device characterized by switching. 2. The apparatus described in item 1 is characterized in that it is equipped with two sets of phasing means that simultaneously form ultrasound beams in two directions, and that the two sets of phasing means are simultaneously switched for the same transmitted wave. Ultrasonic diagnostic equipment.